Part 163

CURAÇOA CORDIAL: See Wines and Liquors.

CURTAINS, COLORING OF: See Laundry Preparations.

CURRY POWDER: See Condiments.

«CUSTARD POWDER:»

Corn flour 7 pounds Arrowroot 8 pounds Oil of almond 20 drops Oil of nutmegs 10 drops Tincture of saffron to color.

Mix the tincture with a little of the mixed flours; then add the essential oils and make into a paste; dry this until it can be reduced to a powder, and then mix all the ingredients by sifting several times through a fine hair sieve.

CUTLERY CEMENTS: See Adhesives.

CYLINDER OIL: See Lubricants.

CYMBAL METAL: See Alloys.

«Damaskeening»

Damaskeening, practiced from most ancient times, consists in ornamentally inlaying one metal with another, followed usually by polishing. Generally gold or silver is employed for inlaying. The article to be decorated by damaskeening is usually of iron (steel) or copper; in Oriental (especially Japanese) work, also frequently of bronze, which has been blackened, or, at least, darkened, so that the damaskeening is effectively set off from the ground. If the design consists of lines, the grooves are dug out with the graver in such a manner that they are wider at the bottom, so as to hold the metal forced in. Next, the gold or silver pieces suitably formed are laid on top and hammered in so as to fill up the opening. Finally the surface is gone over again, so that the surface of the inlay is perfectly even with the rest. If the inlays, however, are not in the form of lines, but are composed of larger pieces of certain outlines, they are sometimes allowed to project beyond the surface of the metal decorated. At times there are inlays again in the raised portions of another metal; thus, Japanese bronze articles often contain figures of raised gold inlaid with silver.

Owing to the high value which damaskeening imparts to articles artistically decorated, many attempts have been made to obtain similar effects in a cheaper manner. One is electro-etching, described further on. Another process for the wholesale manufacture of objects closely resembling damaskeened work is the following: By means of a steel punch, on which the decorations to be produced project in relief, the designs are stamped by means of a drop hammer or a stamping press into gold plated or silver plated sheet metal on the side which is to show the damaskeening, finally grinding off the surface, so that the sunken portions are again level. Naturally, the stamped portion, as long as the depth of the stamping is at least equal to the thickness of the precious metal on top, will appear inlaid.

It is believed that much of the early damaskeening was done by welding together iron and either a steel or an impure or alloyed iron, and treating the surface with a corroding acid that affected the steel or alloy without changing the iron.

The variety or damaskeening known as koftgari or kuft-work, practiced in India, was produced by rough-etching a metallic surface and laying on gold-leaf, which was imbedded so that it adhered only to the etched parts of the design.

«Damaskeening by Electrolysis.»—Damaskeening of metallic plates may be done by electrolysis. A copper plate is covered with an isolating layer of feeble thickness, such as wax, and the desired design is scratched in it by the use of a pointed tool. The plate is suspended in a bath of sulphate of copper, connecting it with the positive pole of a battery, while a second copper plate is connected with the negative pole. The current etches grooves wherever the wax has been removed. When enough has {250} been eaten away, remove the plate from the bath, cleanse it with a little hydrochloric acid to remove any traces of oxide of copper which might appear on the lines of the design; then wash it in plenty of water and place it in a bath of silver or nickel, connecting it now with the negative pole, the positive pole being represented by a leaf of platinum. After a certain time the hollows are completely filled with a deposit of silver or nickel, and it only remains to polish the plate, which has the appearance of a piece damaskeened by hand.

«Damaskeening on Enamel Dials.»—Dip the dial into molten yellow wax, trace on the dial the designs desired, penetrating down to the enamel. Dip the dial in a fluorhydric acid a sufficient length of time that it may eat to the desired depth. Next, wash in several waters, remove the wax by means of turpentine, i. e., leave the piece covered with wax immersed in essence of turpentine. By filling up the hollows thus obtained with enamel very pretty effects are produced.

DANDRUFF CURE: See Hair Preparations.

«DECALCOMANIA PROCESSES:»

See also Chromos, Copying Processes, and Transfer Processes.

The decalcomania process of transferring pictures requires that the print (usually in colors) be made on a specially prepared paper. Prints made on decalcomania paper may be transferred in the reverse to china ware, wood, celluloid, metal, or any hard smooth surface, and being varnished after transfer (or burnt in, in the case of pottery) acquire a fair degree of permanence. The original print is destroyed by the transfer.

«Applying Decalcomania Pictures on Ceramic Products under a Glaze.»—A biscuit-baked object is first coated with a mixture of alcohol, shellac, varnish, and liquid glue. Then the prepared picture print is transferred on to this adhesive layer in the customary manner. The glaze, however, does not adhere to this coating and would, therefore, not cover the picture when fused on. To attain this, the layer bearing the transfer picture, as well as the latter, are simultaneously coated with a dextrin solution of about 10 per cent. When this dextrin coating is dry, the picture is glazed. The mixing proportions of the two solutions employed, as well as of the adhesive and the dextrin solutions, vary somewhat according to the physical conditions of the porcelain, its porosity, etc. The following may serve for an example: Dissolve 5 parts of shellac or equivalent gum in 25 parts of spirit and emulsify this liquid with 20 parts of varnish and 8 parts of liquid glue. After drying, the glaze is put on and the ware thus prepared is placed in the grate fire.

The process described is especially adapted for film pictures, i. e., for such as bear the picture on a cohering layer, usually consisting of collodion. It cannot be employed outright for gum pictures, i. e., for such pictures as are composed of different pressed surfaces, consisting mainly of gum or similar material. If this process is to be adapted to these pictures as well, the ware, which has been given the biscuit baking, is first provided with a crude glaze coating, whereupon the details of the process are carried out as described above with the exception that there is another glaze coating between the adhesive coat and the biscuit-baked ware. In this case the article is also immediately placed in the grate fire. It is immaterial which of the two kinds of metachromatypes (transfer pictures) is used, in every case the baking in the muffle, etc., is dropped. The transfer pictures may also be produced in all colors for the grate fire.

«Decalcomania Paper.»—Smooth unsized paper, not too thick, is coated with the following solutions:

I.—Gelatin, 10 parts, dissolved in 300 parts warm water. This solution is applied with a sponge. The paper should be dried flat.

II.—Starch, 50 parts; gum tragacanth, dissolved in 600 parts of water. (The gum tragacanth is soaked in 300 parts of water; in the other 300 parts the starch is boiled to a paste; the two are then poured together and boiled.) The dried paper is brushed with this paste uniformly, a fairly thick coat being applied. The paper is then allowed to dry again.

III.—One part blood albumen is soaked in 3 parts water for 24 hours. A small quantity of sal ammoniac is added.

The paper, after having been coated with these three solutions and dried, is run through the printing press, the pictures, however, being printed reversed so that it may appear in its true position when transferred. Any colored inks may be used. {251}

IV.—A transfer paper, known as “décalque rapide,” invented by J. B. Duramy, consists of a paper of the kind generally used for making pottery transfers, but coated with a mixture of gum and arrowroot solutions in the proportion of 2 1⁠/⁠2 parts of the latter to 100 of the former. The coating is applied in the ordinary manner, but the paper is only semi-glazed. Furthermore, to decorate pottery ware by means of this new transfer paper, there is no need to immerse the ware in a bath in order to get the paper to draw off, as it will come away when moistened with a damp sponge, after having been in position for less than 5 minutes, whereas the ordinary papers require a much longer time.